The present application is directed to methods and devices for aligning media sheets in an image forming device, and more specifically to correcting misalignment while the media sheet is conveyed along a media feed path.
Image forming devices, such as a color laser printer, facsimile machine, copier, all-in-one device, etc, move media sheets along a media path. The media sheets initially begin at an input tray that is sized to hold a stack of sheets. Each sheet is individually picked from the stack and introduced into the media path. Due to variability in loading the media sheets into the input tray, as well as dimensional tolerances in the media sheets and the input tray, the media sheets in the input tray may not be consistently and properly aligned. This may cause skewing of the media sheets relative to the media path, which may result in print defects. Misalignment may occur in the scan directions (i.e., left and right), as well as the process directions (i.e., forward and backward).
Additionally, the movement of the media sheets from the input area and along the media path should occur without media jams. Media jams require the user to determine the location of the jam, access and remove the jammed sheet(s), and restart the image formation process. Media jams may be caused by misaligned media sheets.
Current methods and devices to correct media sheet misalignment include forcing the leading edge against a gate or roller nip. If the media sheet is misaligned, a leading corner of the leading edge of the media sheet is delayed at the gate or nip. As the sheet is continued to be conveyed by upstream drive rollers, the media sheet buckles and a remaining portion of the leading edge comes into alignment with the leading corner. This method causes a delay in the forward motion of the media sheet, thus limiting the throughput.